Donald Trump disrupted the 2016 election and won many “forgotten Americans” in part by promising to fight for lower prescription drug prices and to tear up or renegotiate the North American Free Trade Agreement (NAFTA), the Trans-Pacific Partnership agreement (TPP) and any other trade agreement that disadvantaged American workers.

His rival for the presidency, former secretary of state Hillary Clinton was hamstrung by her inability to attack these deals: Her husband signed the first into law, while her former boss, President Barack Obama, campaigned to win ratification for the TPP. This restriction left room for candidate Trump to attack the secrecy and special interests that rigged U.S. trade deals to make it easier to outsource American jobs and to make trade a voting issue in the industrial battleground states.

But, ironically, the intensifying debate over the renegotiated NAFTA that President Trump is seeking to rebrand as the United States-Mexico-Canada Agreement (USMCA) suggests that the president’s trade policy is not so different from those of his predecessors. Certainly, the new coalition of 200 corporations and business lobby groups, including Citibank, the American Petroleum Institute and the American Farm Bureau Federation, that just launched a campaign to push Trump’s renegotiated North American trade deal through Congress doesn’t seem to think that there’s anything new in the deal that threatens business-as-usual.

And when told more about what is in “NAFTA 2.0,” voters in surveys and focus groups I’ve conducted this year for Public Citizen have second thoughts about the supposedly new and improved trade deal.

America’s polarized citizenry took a break from intense partisan bickering to produce the highest off-year turnout in a midterm election in 50 years on Nov. 6. Is it possible that all that effort actually nudged us forward a bit?

Because the votes were counted so slowly across the country, we were also slow to realize that Democrats had won the national congressional vote by a margin greater than that of the Tea Party Republicans in 2010. In fact, Democrats overcame huge structural hurdles to win nearly 40 seats.

At first, the results looked like something of a stalemate. The Republican Party retained and even strengthened its hold on the Senate. President Trump’s approval rating was at 45 percent, one percentage point below his percentage of the popular vote in the 2016 election. Analysts said that Mr. Trump still knew how to get Republicans “excited, interested and turn them out” and that he had “deepened his hold on rural areas.”

In the days that followed, though, it became clear that Democrats had made substantial gains. Analysts I trusted concluded that this was because suburban and college-educated women issued “a sharp rebuke to President Trump” that set off a “blue wave through the urban and suburban House districts.” At first, I also believed that was the main story line.

But the 2018 election was much bigger than that. It was transformative, knocking down what we assumed were Electoral College certainties. We didn’t immediately see this transformation because we assumed that Mr. Trump and the polarization in his wake still governed as before.

The 2018 off-year elections in November could be as important to Democrats as the Tea Party, anti-Obamacare off-year 2010 wave that shaped America nationally and locally for almost a decade —if Democrats don’t let ‘em hide from their tax scam for the rich.

And we do not yet know whether Democrats will get it right.

The national generic vote has narrowed and Trump’s approval as creeped up as Democrats stopped contesting health care, Medicare and Medicaid, and the tax cuts and seemed mostly focused on Russians, impeachment and Dreamers. They have deferred to the Republicans on the economy, even though it remains the simple most important determinant of the off-year congressional vote, and the Democratic base and swing voters are deeply suspicious of what Trump and the congressional Republicans are doing passing a tax cut for the rich.

You are not proposing to run in 2018 proposing to raise taxes? Yes. Yes. We will raise taxes on the rich. Count on it. Voters view that as the most important thing we can do to reverse their corrupt course. Does anybody remember that Bill Clinton and Barak Obama ran election and re-election promising to raise taxes on the rich?

Political commentators and strategists write with some awe of President Trump’s outrageous, gutsy strategy of ginning up his base with one more attack on black athletes, one more crackdown on Central American mothers and children on the Mexican border, one more assault on Obamacare, one more tariff on imports. They think Mr. Trump’s drumbeat is intensifying loyalty and fervor among Republican partisans and that the Republican Party we used to know is “taking a nap somewhere,” as John Boehner, the former speaker of the House, put it.

Much more worrisome for those of us who think the country needs a blue wave is the way Mr. Trump’s strategy appears to be raising his job approval ratings and closing the enthusiasm gap with Democrats that has been a critical element in the handful of off-year elections since 2016. Any wave election worth its salt — like the 1974 Watergate cleansing, the 1994 Gingrich revolution or the 2010 Tea Party election — is produced by the elevated energy and enthusiasm of one party and the demoralization and fracturing of the other.

Well, Mr. Trump’s base strategy is producing precisely that kind of enthusiasm gap in the polls I am conducting for Democracy Corps and its partners, Women’s Voices, Women Vote and the American Federation of Teachers. This gap shows up precisely because while Mr. Trump’s strategy is to build up support with Tea Party supporters and evangelicals who make up a plurality of those who identify as Republicans, they are by no means the whole of the party. Mr. Trump shows as much interest in winning over those less enthusiastic Republicans as he does in winning independents and Democrats — which is to say, not much.

Get yourself into a totally different mindset when you try to understand this year’s US mid-term elections. Congressional elections are, of course, no rare thing. They happen every two years, and when the White House is not up for grabs, the President can normally expect a bit of a bruising. But this time around, we can look out for something more significant.

November’s vote will almost certainly kick off a new progressive era of reform, much like the cluster of elections, starting with the 1910 mid-terms, which launched America’s first progressive era.